DOE OSTI2020
AlC crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of twenty-four aluminium molecules and one AlC5 sheet oriented in the (0, 0, 1) direction. In the AlC5 sheet, there are six inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a distorted L-shaped geometry to three C3- atoms. There are a spread of Al–C bond distances ranging from 2.17–2.46 Å. In the second Al3+ site, Al3+ is bonded in a 2-coordinate geometry to two C3- atoms. There are one shorter (2.05 Å) and one longer (2.31 Å) Al–C bond lengths. In the third Al3+ site, Al3+ is bonded in a 2-coordinate geometry to two C3- atoms. There are one shorter (2.05 Å) and one longer (2.32 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded in a water-like geometry to two C3- atoms. Both Al–C bond lengths are 2.27 Å. In the fifth Al3+ site, Al3+ is bonded in a single-bond geometry to one C3- atom. The Al–C bond length is 2.07 Å. In the sixth Al3+ site, Al3+ is bonded in a single-bond geometry to one C3- atom. The Al–C bond length is 2.07 Å. There are thirty inequivalent C3- sites. In the first C3- site, C3- is bonded to one Al3+ and three C3- atoms to form distorted corner-sharing CAlC3 tetrahedra. There are a spread of C–C bond distances ranging from 1.51–1.60 Å. In the second C3- site, C3- is bonded to one Al3+ and three C3- atoms to form corner-sharing CAlC3 tetrahedra. There are a spread of C–C bond distances ranging from 1.53–1.59 Å. In the third C3- site, C3- is bonded to one Al3+ and three C3- atoms to form corner-sharing CAlC3 tetrahedra. There is one shorter (1.44 Å) and two longer (1.57 Å) C–C bond length. In the fourth C3- site, C3- is bonded in a distorted trigonal non-coplanar geometry to three C3- atoms. There are a spread of C–C bond distances ranging from 1.44–1.56 Å. In the fifth C3- site, C3- is bonded in a 5-coordinate geometry to two Al3+ and three C3- atoms. There are a spread of C–C bond distances ranging from 1.53–1.63 Å. In the sixth C3- site, C3- is bonded in a distorted pentagonal planar geometry to two Al3+ and three C3- atoms. Both C–C bond lengths are 1.63 Å. In the seventh C3- site, C3- is bonded in a distorted trigonal non-coplanar geometry to three C3- atoms. There is one shorter (1.55 Å) and one longer (1.56 Å) C–C bond length. In the eighth C3- site, C3- is bonded to one Al3+ and three C3- atoms to form corner-sharing CAlC3 tetrahedra. Both C–C bond lengths are 1.57 Å. In the ninth C3- site, C3- is bonded to one Al3+ and three C3- atoms to form corner-sharing CAlC3 tetrahedra. There is one shorter (1.58 Å) and one longer (1.59 Å) C–C bond length. In the tenth C3- site, C3- is bonded to one Al3+ and three C3- atoms to form distorted corner-sharing CAlC3 tetrahedra. There is one shorter (1.58 Å) and one longer (1.60 Å) C–C bond length. In the eleventh C3- site, C3- is bonded in a 4-coordinate geometry to one Al3+ and four C3- atoms. Both C–C bond lengths are 1.53 Å. In the twelfth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. There is one shorter (1.55 Å) and one longer (1.56 Å) C–C bond length. In the thirteenth C3- site, C3- is bonded to four C3- atoms to form corner-sharing CC4 tetrahedra. There is one shorter (1.53 Å) and one longer (1.54 Å) C–C bond length. In the fourteenth C3- site, C3- is bonded to four C3- atoms to form corner-sharing CC4 tetrahedra. There is one shorter (1.53 Å) and one longer (1.54 Å) C–C bond length. In the fifteenth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. There is one shorter (1.55 Å) and one longer (1.56 Å) C–C bond length. In the sixteenth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. Both C–C bond lengths are 1.52 Å. In the seventeenth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. There is one shorter (1.53 Å) and one longer (1.56 Å) C–C bond length. In the eighteenth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. Both C–C bond lengths are 1.54 Å. In the nineteenth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. There is one shorter (1.53 Å) and one longer (1.56 Å) C–C bond length. In the twentieth C3- site, C3- is bonded to four C3- atoms to form distorted corner-sharing CC4 tetrahedra. Both C–C bond lengths are 1.52 Å. In the twenty-first C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-second C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-third C3- site, C3- is bonded in a water-like geometry to two C3- atoms. In the twenty-fourth C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-fifth C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-sixth C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-seventh C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the twenty-eighth C3- site, C3- is bonded in a water-like geometry to two C3- atoms. In the twenty-ninth C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms. In the thirtieth C3- site, C3- is bonded in a bent 120 degrees geometry to two C3- atoms.